A tree by any other name ....
"If I had wanted to memorize so many names, I would have become a botanist."
The Nobel prize-winning physicist was expressing his dismay at the ever-growing list of names--quarks, neutrinos, leptons, gluons, bosons, etc.--for the ever-smaller particles of matter that he and his colleagues were discovering. But in a roundabout way he was also commenting on the rigors of plant nomenclature. The history of tree names is a fascinating but dizzying account of frustration and confusion.
Imagine you were skiing with friends through the back woodlot recently. As you entered a stand of balsam fir, one of your friends held forth on the beauty of those snow-covered "evergreens." Another friend called them "pine trees." Didn't the farmer up the road call them "Balm O'Gilead?" Then again, the old-time forester you had in a few months back said those "blister pines" sure were making good growth. His young intern saw it differently. She said the deer use those "fir" as a wintering yard. Of course, identical trees at the local landscape nursery are labeled "silver pine." And when your uncle, the retired professor of botany, came for a visit, he said that beyond a shadow of a doubt those were "Abies balsamea." Your kids call them "Christmas trees."
It's true. Most trees have a couple of names, and some have dozens. Perhaps worse, though, is when the same name is used for several different species. Millions of homeowners proudly walk on "yellow pine" floors. They might be made from any of 10 southern yellow pines, most likely: longleaf, shortleaf, slash, or loblolly. On the other hand, there are at least another dozen or so "yellow pines" in the West, including ponderosa, Jeffrey, and lodgepole--although these are probably better for interior moldings than flooring.
Still with me? Consider the oaks; they're notoriously difficult to identify. And even when you do, there remains the challenge of keeping their names straight. The confusion usually starts with the two broad categories into which oaks are lumped: the "white oaks" and the "red oaks."
There are some good reasons for the separation. Red oaks have bristle-tipped leaves, white oaks don't; red-oak acorns need two years to mature, white-oak acorns need only one. Perhaps more important is the practical advantage held by white-oak wood--it tends to be more watertight.
The real question, however, is not whether to separate the oaks into two classes but rather why to call them "red oaks" and "white oaks"? Nobody seems to be very sure of the answer, but the smart money says that the basis lies in the general color of the wood--the wood of all species of white oaks is lighter-colored than the pink-tinged, salmon-hued wood of the red oaks.
Foremost among the white-oak group is "eastern white oak," heralded for its unrivaled spread of branches. However, it is not to be confused with "swamp white oak"--known for its contrasty, two-color leaves, green above and whitish underneath, and plainly different from the "swamp post oak," whose acorns are over-cupped. You'd never confuse it with the scrubby but utilitarian "post oak." And don't forget "chinquapin oak"; it is easily separated from the "chinquapin," which is not an oak but a chestnut and is altogether different from the "chestnut oak."
The red-oak group can be just as confusing. "Northern red oak" (also called "gray oak" because of its bark) is, at least mostly, geographically separated from "southern red oak," known to some as "Spanish oak" but never to be mistaken for "scarlet oak," whose blazing red leaves easily distinguish it from the "Shumard red oak." If you find those easy to sort out, try "black oak," a member of the red-oak group, once known for its importance in making yellow dye!
The list is endless. The tuliptree--also known as tulip, yellow, or white poplar--is neither a tulip nor a poplar. It's a magnolia, of course. Winged elm and slippery elm are different species, but both are alternatively referred to as red elm. Arborvitae, the tree-of-life, which counts among its many aliases cedar and northern white cedar, technically is more of a cypress than a cedar. And no forestry-school graduate is ever likely to forget the tribulations of sorting out American hornbeam (AKA blue beech, musclewood, or ironwood) from American hophornbeam (AKA ironwood). The latter ironwood has shredded, gray-brownish bark; the former ironwood has fluted, bluish bark. To your saw there's no difference; they're both damn hard.
Outside the halls of academia, tree parlance typically involves so-called "common names." But as we've all experienced, the label "common" is not without problem. Some common names--like common sense--aren't common at all. Rather, they are used only in a very limited area or time. Maybe "vernacular" is a more precise designation.
So how do trees get their vernacular (AKA common, popular, English, or non-scientific) names? Often, but not always, such monikers are based on some unique characteristic of the tree. The connection between a distinctive morphological feature of a tree and its name is relatively obvious: shagbark hickory, bigleaf maple, longleaf pine, and quaking aspen. The site or habitat where a tree is often found is also commonly invoked in names: sub-alpine fir, swamp white oak, bog spruce, and river birch. The region of a species' prominence is another source for names: western hemlock, eastern cottonwood, southern balsam, and northern red oak. Other names derive from a tree's use: canoe birch, basket ash, sugar maple, and pitch pine. And some names are adaptations from other languages: catalpa (Cherokee), arborvitae (Latin), and encine (Spanish).
These derivations make some sense, but unfortunately, confusion and its sinister pal frustration usually have their way. As we have seen, vernacular names can be misleading, and no hard and fast rules apply. Some species are called by many different names, and sometimes the same name is used for different species. This has been perhaps the strongest argument for the development of a set of rules governing a universal system of nomenclature.
The apparent chaos notwithstanding, the whole of plant classification is based on order. "Taxonomy," from the Greek Taxis, for order, is the business of systematically arranging plants in a definite order. It is not a new business. Theophrastus was at it in the fourth century B.C., and Pliny the Elder made some headway in the first century A.D. From these early works based on general descriptive terms, the process evolved over centuries.
Many botanists contributed mightily, but it was not until 1753, when the Swedish naturalist Carl Ritter von Linne published Species Plantarum, that the system of "binomial nomenclature" was introduced. With minor modifications, it is still with us as the basis of modern "scientific names." Latin was used in the binomial system of names since it was the language used customarily by scientists of all countries. It is still used today because, as a "dead language," it is not prone to change.
Incidentally, there is a remarkable irony in the history of this tree-name mess. Even the name of the "father of taxonomy" himself is shrouded in confusion. He was Linne, but his name usually appears as "Linnaeus," which, in keeping with the custom of his day, was written in the Latin form.
Today basic taxonomy divides the plant kingdom into divisions and then classes, orders, families, genera, and species. According to the Linnaean system, just two words are needed for the scientific name of a tree: the name of the genus (singular of genera) followed by that of the species. Often in scientific publications this two-part name is followed by the name or abbreviated name of the person who published the first description of the species. Under this system, northern red oak is officially known as Quercus rubra Linnaeus.
There is an entire set of provisions governing everything from the naming of new species, hybrids, and cultivars to the spelling and syntax of well-established species. These rules of coinage and use are outlined in the "International Code of Botanical Nomenclature," which itself is governed by the periodically convened "International Botanical Congress." Don't be fooled by the official and orderly tone; the rules change even more than the names.
All these congresses and rules are supposed to make the use of scientific nomenclature easier. On the contrary, it is ripe with confusion. Acer, the genus of all maples, is from the Celtic ac, for "hard," which is a characteristic of maple wood. Rubra is the Latin word for red. Thus Acer rubra is the scientific name for red maple, right? Wrong. The maples are known for inconsistencies in their names. As it happens, red maple is officially Acer rubrum. The "-um" perhaps being attached to maintain consistency with Acer saccharum, also known as sugar maple, the saccharum being Latin for sweet or sugar. Then again, silver maple is Acer saccharinum, considered by some scholars to be a misspelling of saccharum.
It is fitting that the king of American lumber species would also qualify as the king of confusing names. "Douglas-fir" (Pseudotsuga menziesii) is hyphenated because the tree isn't a fir. And it wasn't first identified by Douglas either. It was first described by the Scottish naturalist Archibald Menzies, from whom the species takes its epithet, menziesii. The common name commemorates David Douglas, another Scot who studied it later. Its first scientific name was Pinus taxifolia. The genus was so named because many thought it was a pine. Then they thought it looked like a hemlock and changed it to Pseudotsuga, which is Latinized from Greek and Japanese for "false hemlock." The earlier species name, taxifolia, is owing to its yew-like (Taxus) foliage (folia). To keep things interesting, Douglas-fir has been marketed variously as Oregon pine, bigcone spruce, blue spruce, yellow fir, and red fir. Go figure.
Even if you manage to overcome the confusion of what to call a particular tree, your problems aren't over. Just when you start to get comfortable with tree names--when you think you might head on out and call a tree by its internationally recognized scientific name--you are faced with yet another utterly nettlesome quandary: pronunciation.
In the event you and a fellow tree-namer settle on a tree's identification, chances are he'll pronounce it differently. Is the "c" in Acer hard or soft? Is the "A" in Abies long or short? Which syllables are emphasized in Liriodendron tulipifera, (LEE-rio-DEN-dron TULIP-ifera) or Liquidambar styraciflua (LIQUID-ambar STY-rasi-FLUWA). And just how does one pronounce Metasequoia glyptostroboides?
No wonder Fermi chose particle physics. At least a quark is a quark (for now). Sorting through the seemingly endless duplication, synonymy, and outright confusion of tree names can be a daunting affair. The problem is that there are so many good reasons and rationales for any given tree species' name, be it vernacular or scientific. What is red to one is black to another. What is big to him is small to her. What is west to me is east to you.
Think about it. Trees are named for a whole litany of fine reasons, from site (water tupelo, Nyssa aquatica) to country (Canada yew, Taxus canadensis), from shape of leaves (bigtooth aspen, Populus grandidentata) to color of bark (whitebark pine, Pinus albicualis). They are named for Euro-Americans (Engelmann spruce, Picea engelmannii) and Native Americans (Giant Sequoia, Sequoiadendron giganteum), for poisons (poison sumac, Toxicodendron vernix) and for sweets (sugar maple, Acer saccharum).
But in the end, it is the trees that matter, not necessarily their names. When you are faced with some intractable tree-name mystery, remember two points. First, the correct name for a tree is the one that is understood by those with whom you communicate. And second, the trees don't care.
Michael Snyder is a freelance writer and a research forester at the University of Vermont.
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|Title Annotation:||tree classification|
|Date:||Nov 1, 1993|
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